ADD: new track message, Entity class and Position class

libs/eigen/cmake/FindGMP.cmake

@@ -0,0 +1,21 @@
+# Try to find the GNU Multiple Precision Arithmetic Library (GMP)
+# See http://gmplib.org/
+
+if (GMP_INCLUDES AND GMP_LIBRARIES)
+  set(GMP_FIND_QUIETLY TRUE)
+endif ()
+
+find_path(GMP_INCLUDES
+  NAMES
+  gmp.h
+  PATHS
+  $ENV{GMPDIR}
+  ${INCLUDE_INSTALL_DIR}
+)
+
+find_library(GMP_LIBRARIES gmp PATHS $ENV{GMPDIR} ${LIB_INSTALL_DIR})
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(GMP DEFAULT_MSG
+                                  GMP_INCLUDES GMP_LIBRARIES)
+mark_as_advanced(GMP_INCLUDES GMP_LIBRARIES)